The
Mexican-American War was the first major conflict
driven by the idea of "Manifest Destiny"; the
belief that America had a God-given right, or
destiny, to expand the country's borders from 'sea
to shining sea'. This belief would eventually cause
a great deal of suffering for many Mexicans, Native
Americans and United States citizens. Following the
earlier Texas War of Independence from Mexico,
tensions between the two largest independent
nations on the North American continent grew as
Texas eventually became a U.S. state. Disputes over
the border lines sparked military confrontation,
helped by the fact that President Polk eagerly
sought a war in order to seize large tracts of land
from Mexico.

CAUSES OF
CONFLICT:

The war between the
United States and Mexico had two basic causes.
First, the desire of the U.S. to expand across the
North American continent to the Pacific Ocean
caused conflict with all of its neighbors; from the
British in Canada and Oregon to the Mexicans in the
southwest and, of course, with the Native
Americans. Ever since President Jefferson's
acquisition of the Louisiana Territory in 1803,
Americans migrated westward in ever increasing
numbers, often into lands not belonging to the
United States. By the time President Polk came to
office in 1845, an idea called "Manifest Destiny"
had taken root among the American people, and the
new occupant of the White House was a firm believer
in the idea of expansion. The belief that the U.S.
basically had a God-given right to occupy and
"civilize" the whole continent gained favor as more
and more Americans settled the western lands. The
fact that most of those areas already had people
living upon them was usually ignored, with the
attitude that democratic English-speaking America,
with its high ideals and Protestant Christian
ethics, would do a better job of running things
than the Native Americans or Spanish-speaking
Catholic Mexicans. Manifest Destiny did not
necessarily call for violent expansion. In both
1835 and 1845, the United States offered to
purchase California from Mexico, for $5 million and
$25 million, respectively. The Mexican government
refused the opportunity to sell half of its country
to Mexico's most dangerous neighbor.

The second basic
cause of the war was the Texas War of Independence
and the subsequent annexation of that area to the
United States. Not all American westward migration
was unwelcome. In the 1820's and 1830's, Mexico,
newly independent from Spain, needed settlers in
the underpopulated northern parts of the country.
An invitation was issued for people who would take
an oath of allegiance to Mexico and convert to
Catholicism, the state religion. Thousands of
Americans took up the offer and moved, often with
slaves, to the Mexican province of Texas. Soon
however, many of the new "Texicans" or "Texians"
were unhappy with the way the government in Mexico
City tried to run the province. In 1835, Texas
revolted, and after several bloody battles, the
Mexican President, Santa Anna, was forced to sign
the Treaty of Velasco in 1836 . This treaty gave
Texas its independence, but many Mexicans refused
to accept the legality of this document, as Santa
Anna was a prisoner of the Texans at the time. The
Republic of Texas and Mexico continued to engage in
border fights and many people in the United States
openly sympathized with the U.S.-born Texans in
this conflict. As a result of the savage frontier
fighting, the American public developed a very
negative stereotype against the Mexican people and
government. Partly due to the continued hostilities
with Mexico, Texas decided to join with the United
States, and on July 4, 1845, the annexation gained
approval from the U.S. Congress.

Mexico of course
did not like the idea of its breakaway province
becoming an American state, and the undefined and
contested border now became a major international
issue. Texas, and now the United States, claimed
the border at the Rio Grande River. Mexico claimed
territory as far north as the Nueces River. Both
nations sent troops to enforce the competing
claims, and a tense standoff ensued. On April 25,
1846, a clash occurred between Mexican and American
troops on soil claimed by both countries. The war
had begun.

DESCRIPTION
OF CONFLICT:

The
Mexican-American War was largely a conventional
conflict fought by traditional armies consisting of
infantry, cavalry and artillery using established
European-style tactics. As American forces
penetrated into the Mexican heartland, some of the
defending forces resorted to guerrilla tactics to
harass the invaders, but these irregular forces did
not greatly influence the outcome of the war.

After the beginning
of hostilities, the U.S. military embarked on a
three-pronged strategy designed to seize control of
northern Mexico and force an early peace. Two
American armies moved south from Texas, while a
third force under Colonel Stephen Kearny traveled
west to Sante Fe, New Mexico and then to
California. In a series of battles at Palo Alto and
Resaca de Palma (near current-day Brownsville,
Texas), the army of General Zachary Taylor defeated
the Mexican forces and began to move south after
inflicting over a thousand casualties. In July and
August of 1846, the United States Navy seized
Monterey and Los Angeles in California. In
September, 1846, Taylor's army fought General
Ampudia's forces for control of the northern
Mexican city of Monterey in a bloody three-day
battle. Following the capture of the city by the
Americans, a temporary truce ensued which enabled
both armies to recover from the exhausting Battle
of Monterey. During this time, former President
Santa Anna returned to Mexico from exile and raised
and trained a new army of over 20,000 men to oppose
the invaders. Despite the losses of huge tracts of
land, and defeat in several major battles, the
Mexican government refused to make peace. It became
apparent to the Polk Administration that only a
complete battlefield victory would end the war.
Continued fighting in the dry deserts of northern
Mexico convinced the United States that an overland
expedition to capture of the enemy capital, Mexico
City, would be hazardous and difficult. To this
end, General Winfield Scott proposed what would
become the largest amphibious landing in history,
(at that time), and a campaign to seize the capital
of Mexico.

On March 9, 1847,
General Scott landed with an army of 12,000 men on
the beaches near Veracruz, Mexico's most important
eastern port city. From this point, from March to
August, Scott and Santa Anna fought a series of
bloody, hard-fought battles from the coast inland
toward Mexico City. The more important battles of
this campaign include the Battles of : Cerro Gordo
(April 18), Contreras (August 20), Churubusco
(August 20), Molino del Rey (September 8) and
Chapultepec (September 13). Finally, on September
14, the American army entered Mexico City. The
city's populace offered some resistance to the
occupiers, but by mid-October, the disturbances had
been quelled and the U.S. Army enjoyed full
control. Following the city's occupation, Santa
Anna resigned the presidency but retained command
of his army. He attempted to continue military
operations against the Americans, but his troops,
beaten and disheartened, refused to fight. His
government soon asked for his military resignation.
Guerrilla operations continued against Scott's
lines of supply back to Veracruz, but this
resistance proved ineffective.

On February 2,
1848, The Treaty of Guadeloupe Hidalgo was signed,
later to be ratified by both the U.S. and Mexican
Congresses. The treaty called for the annexation of
the northern portions of Mexico to the United
States. In return, the U.S. agreed to pay $15
million to Mexico as compensation for the seized
territory. The bravery of the individual Mexican
soldier goes a long way in explaining the
difficulty the U.S. had in prosecuting the war.
Mexican military leadership was often lacking, at
least when compared to the American leadership. And
in many of the battles, the superior cannon of the
U.S. artillery divisions and the innovative tactics
of their officers turned the tide against the
Mexicans. The war cost the United States over $100
million, and ended the lives of 13,780 U.S.
military personnel. America had defeated its weaker
and somewhat disorganized southern neighbor, but
not without paying a terrible price.

CONSEQUENCES OF
CONFLICT:

1.
The United States acquired the northern half of
Mexico. This area later became the U.S. states
of California, Nevada, Arizona, New Mexico and
Utah.

2.
President Santa Anna lost power in Mexico
following the war.

3. U.S.
General Zachary "Old Rough and Ready" Taylor
used his fame as a war hero to win the
Presidency in 1848. A true irony is that
President Polk, a Democrat, pushed for the war
that led to Taylor, a Whig, winning the White
House.

4.
Relations between the United States and
Mexico remained tense for many decades to come,
with several military encounters along the
border.

5. For
the United States, this war provided a
training-ground for the men who would lead the
Northern and Southern armies in the upcoming
American Civil War.

UNIQUE FACTS OR
TRENDS:

1.
This war featured the first major amphibious
landing by U.S. forces in history.

2. The
defeat of Mexico was the first time an enemy
force occupied the capitol of the nation. The
French would also occupy Mexico City in the
1860's.

3.
Despite early popularity at home, the war
was marked by the growth of a loud anti-war
movement which included such noted Americans as
Ralph Waldo Emerson, former president John
Quincy Adams and Henry David Thoreau. The center
of anti-war sentiment gravitated around New
England, and was directly connected to the
movement to abolish slavery. Texas became a
slave state upon entry into the
Union.

4. One
interesting aspect of the war involves the fate
of U.S. Army deserters of Irish origin who
joined the Mexican Army as the Batallón
San Patricio (Saint Patrick's Battalion). This
group of Catholic Irish immigrants rebelled at
the abusive treatment by Protestant,
American-born officers and at the treatment of
the Catholic Mexican population by the U.S.
Army. At this time in American history,
Catholics were an ill-treated minority, and the
Irish were an unwanted ethnic group in the
United States. In September, 1847, the U.S. Army
hanged sixteen surviving members of the San
Patricios as traitors. To this day, they are
considered heroes in Mexico.

5. In Mexico, a
special day is remembered to celebrate the
bravery of the teenaged military cadets at the
military academy at Chapultepec Castle, which
was attacked by Scott's army on September 13,
1847. "Dia de Los Niños Heroes de
Chapultepec" ("day of the boy heroes of
Chapultepec), is commemorated every year on the
anniversary of the battle.

Ordered to
retreat by their Commandant, these young cadets
joined the fight- the boy heroes who are honored
every year are the four teenaged cadets
(Francisco Marquez, the youngest, was thirteen
years old!) and their lieutenant squadron
leader, Juan de la Barrera, (the oldest, age
20), who lost their lives in that
battle.

CASUALTY
FIGURES:

United
States-- 13,780 dead, many more wounded.

Mexico--
Much higher than the U.S. total. One figure
put Mexican casualties at approximately
25,000.

ELEMENTS
OF
CONTROVERSY--Very
interesting article on the San
Patricio Battalion, a unit in the
Mexican army made up of
Irish-American deserters. This
author looks at the controversy
around these "traitors", from the
Mexican and Irish viewpoint.
Worth reading!

Invasion
Yanqui--Contains
pictures of the U.S.-Mexican War
and the San Patricios.

The
San
Patricios--Website
of Day Communications, makers of
a factual documentary on Mexico's
Irish soldiers.

The
Mexican-American War Memorial
Homepage--
Presents the war from the Mexican
perspective. Very interesting,
and is available in both Spanish
and English. The English
translation is a bit rough in its
grammar, but is worth
reading.

1.
The United States acquired the northern
half of Mexico. This area later became the
U.S. states of California, Nevada,
Arizona, New Mexico and Utah.

2.
President Santa Anna lost power in Mexico
following the war.

3.
U.S. General Zachary "Old Rough and Ready"
Taylor used his fame as a war hero to win
the Presidency in 1848. A true irony is
that President Polk, a Democrat, pushed
for the war that led to Taylor, a Whig,
winning the White House.

4.
Relations between the United States and
Mexico remained tense for many decades to
come, with several military encounters
along the border.

5.
For the United States, this war provided a
training-ground for the men who would lead
the Northern and Southern armies in the
upcoming American Civil War.